Arrangement for valve transmitters



June 20, 1933. w BUSCHBECK 1,914,593

ARRANGEMENT FOR VALVE TRANSMITTERS Filed D60. 15, 1928 awue'ntoz WERNER BUSCHBECK I 3515 Ri Gimme/13%; a 4

Patented June 20, 1933 UNITED STATES PATENT OFFICE WERNER IBUgCI-IBECK, OF BERLIN, GERMANY, ASSIGNOR T0 TELEFUNKEN GESEL'L- SCIIAFT FUR DRAHTLOSE TELEGRAPHIE M. B. H., 0F BERLIN, GERMANY, A CORPO- RATION 0F GERMANY ARRANGEMENT FOR VALVE TRANSMITTERS Application filed December 15, 1928, Serial No. 326,276, and in Germany December 29, 1927.

It has been found particularly in the operation of valve transmitters that cable and supply leads connected at points which inherently include reactances may be practically free from radio frequency potentials at the working wave but yet are liable to assist in producing disturbing oscillations in the circuits in which they are included. These troublesome oscillations, as is well known, are generally at high frequencies. The presence of these disturbing oscillations causes many disadvantages notably among them being the fact that they are apt to damage the tube or other parts of the equipment and to produce howling and in general to prevent quiet operation of the circuits.

It is one of the objects of this invention to prevent the deduction of these oscillations in a manner which will not in any Way undermine the efiiciency of the system.

Other objects of the invention will appear in the following detailed description of the invention when read in connection with the drawing in which, the single figure represents diagrammatically one embodiment of my invention applied to a transmitting circuit.

In order to prevent the production of these oscillations due to the reactances of the supply leads or any other leads carrying working potentials according to this invention, an ohmic resistance shunted by a choke-coil is connected therein. The provision of a choke-coil alone would not suflice to afford protection, for the choke-coil is apt to cause sufficient reactances to start the circuit to oscillating at a period, determined in part by the value of the choke-coil while the use of an ohmic resistance without a choke-coil, in turn, is prohibitive on account of the incidental drop of potential and the energy consumption associated therewith.

The provision of resistances and of chokecoils in parallel thereto is recommendable in valve transmitters for the supply leads furnishing potential to the plates, for the filament supply lead and especially, for leads furnishing biasing potentials to the grids.

One stage of a separately-excited (pilot or absorber) valve transmitter outfit is shown in the accompanying drawing merely for purposes of illustration. The filament circuit comprising +A, -A, the plate feed lead +B and the grid biasing lead G contain choke-coils D shunted by ohmic resistances TV according to the invention.

It will be understood that I do not desire to limit myself to the cases covered here merely for purposes of illustration but that the basic idea of the invention will be found useful also in other circuit arrangements for tubes, and that they will come within the scope of the appended claims.

Having thus described my invention what I claim is:

Means for relaying high frequency oscillations which are represented by a substantially pure sine wave including, a thermionic tube having an anode, a cathode, and a control electrode, a high frequency circuit connecting said anode to said cathode, a high frequency circuit connecting said control electrode to said cathode, conductive means for applying direct current potentials to each electrode in said tube, and means for preventing oscillations from arising in said circults due to the inherent reactance of said conductive means comprising an inductance in parallel with a resistance in each conductive means.

WERNER BUSCHBECK. 

